Thermostat control for domestic water heaters



Patented Nov. 24, 1942 raamosrsr coN'raoL Foa nonas'nc wam mms Ernst B. Koppel. Wauwatosa, Wis., assigner to Ar" 0. Smith Corporation, Milwaukee, Wis.,l a oorporation of New York Application May 6, 1940, Serial No. 333,613

2 Claims. (Cl. 236-20) This invention relates to thermostat control for domestic water heaters.

Heretofore controls for gas heaters have been designed to extend outside of'the outer casing of the heater and together with the piping they constituted an unsightly appearance.` This has seriously aii'ected the stream lined appearance attempted to be given to domestic water heaters.

Furthermore, the placing of the valves and adjustment mechanism on the outside exposes them to improper handling by children and others.

The principal object of the present invention is to provide a thermostat control and valve construction which is ntirely enclosed in the stream lined casing oi the heater.

Another Objectis to provide a control employlng standard valve mechanism with a more simple and less costly arrangement of the control.

Other objects will appear hereinafter in connection with the description of the preferred embodment ofl the invention illustrated in the accompanying drawing.

In the drawing:

Figure l'is a' front elevation of a part of a domestic water heater with the door 22 removed to show the arrangement of the gas control and burner which are normally concealed thereby;

Fig. 2 is a transverse section taken on line 2--2 of Fig. l showing the front of the tank and the controls;

Fig. 3 is a vertical section taken on line 2 2 of Fig. 1 showing the control valves in side elevation;

Fig. 4 is a vertical section taken on line I-l of Fig. 1 showing the water heating thermostat and control valve; and

Fig. 5 is a vertical section taken on line l-l of Fig. 1 showing the pilot thermostat and control valve.

In accordance with the invention the gas supply pipe I connects with the control devices beneath the tank 2. The tank 2 which is connected to the water system for the house. is supported on legs 3 which are fastened to the heater bottom 4. A casing 5 covers the tank and insulation G fills the space therebetween. Legs 1 preferably in registry with legs 3 support the structure.

The control devices constitute two units, the thermostat lvalve I2a, which is attached to the tank 2, and the safety pilot and shut ofi' valve assembly I2 which is attached to Vone of the legs 3. For this purpose the tank 2 has a depression above the bottom and a threaded bushing l is provided'in the depression to receive the main water heater thermostat III which extendsinto the tank, and theleg 3 has a lug II welded thereto for attachment to the lower valve casing tank.

'I'he safety pilot and shut oil valve assembly I2 has a threaded opening for receiving the supply pipe I and vcarries a pilot burner Il and a pilot thermostatl. Inside the casing I2 a bypass I1 feeds the pilot burner with gas from the main supply. A manually operated rotary valve Il opens or` closes the gas to the pilot burner and is adjustable by means of screw I la. The thermostat Il operates a shut-oil valve I9 in the casing I2 to shut off the main supply to the burner when the pilot becomes extinguished.

In operation the gas enters through supply pipe I to casing I2 where a small amount passes through the bypass Il and valve I8 to the pilot burner Il. Assuming that the burner I5 is lighted, the thermostat I 8 becomes hot and allows the shut-on valve Il to open allowing the gas to pass from casing I2 through pipe 2l to'the chamber of valve I2. The water in tank 2 being cold. the thermostat Il has already opened 'valve I3 and the gas passes through this valve and down through pipe 2| to the burner Il. When the water in tank 2 becomes heated to the desired temperature, the thermostat Il operates valve Il to shut oi! the gas supply.

The construction of the thermostats III and Il and of the control valves IJ and I9 may be conventional and need not be described in detail. The invention relates to the arrangement in which the gas supply pipe .connects at the bottom and the valves are disposed close to the tank, inside the casing l so as to protect the same from injury and improve the appearance of the heater.

In the'construction shown, a door 22 is hinged or otherwise secured to the outer casing to cover.

the control devices. The control devices are disposed in a pocket 23 in the insulation 6. In addition to this, an opening 2| between the tank 2 and frame l, also covered by the door 22, provides space for inserting the burner Il and sub# sequently furnishes access to light the pilot I5 8 formed in its side wall at a suitable distance 55 and to clean the burner.

casing.,

Various embodiments of the invention may be employed within the scope of the claims.

The invention is claimed as follows:

1. In combination, a domestic water heater storage tank of generally upright cylindrical shape, a. gas burner below the tank, a central flue passing upwardly through the tank for the gas fumes, heat insulation surrounding the tank, a cylindrical outer casing enclosing the tank and insulation and providing a space of substantially uniform minimum thickness for said insulation between the casing and tank, said tank wall having an angular depression therein for receiving a thermostat, a thermostat element extending into the tank through the wall of the depression, said element extending normal to said wall and at an angle to theradius of the tank to avoid engaging said flue, a valve casing disposed in ,the depression in said tank wall and the spacebetween it'and the outer casing, a valve in said valve casing operated by saidthermostat, and ppc connections for supplying gas. through said valve to the burner, said connectionsbeing lo-e cated substantially entirely within said outer 2. Incombination in a domestic water heater having Van upright cylindrical storage tank with a heating burner therebeneath, a cylindrical casing surrounding the tank. and providing a space of substantially uniform thickness be` the wall of the tank at an angle to the tank radius in said depression, the control mechanism of said thermostat and valve being disposed partially within said depression and substantially mechanism.

within the radius of said outer casing, and a re- .movable cover plate over the opening in saidy outer casing for providing access to said control ERNST a. KOPPEL 

